1,3-Dipolar Cycloaddition in Polymer Synthesis. 1. Polyadducts with Flexible Spacers Derived from Bis(<i>N</i>-methylnitrone)s and Bis(<i>N</i>-phenylmaleimide)s

Abstract

The thermal 1,3-dipolar polycycloaddition of N,N‘-dimethyl-p-phenylenedinitrone (3) and 4,4‘-hexanediyldioxydi(N-methyl-p-phenylenenitrone) (10) with N,N‘-(1,4-phenylene)dimaleimide and 1,6-hexanediylbis(carbamic acid) bis(N-methyl-p-phenylenenitrone) ester (12) with 1,6-hexanediylbis(carbamic acid) bis[N-(p-phenylene)maleimide] ester (16) in DMF solution and nitrogen atmosphere lead to the formation of corresponding polyadducts 5, 13 and 17. The comparison of 1H NMR, 13C NMR and IR spectra of a model compound 2-methyl-3-(4‘-hydroxyphenyl)isoxazolidine-4,5-dicarboxyphenylimide (8) with model polymer 5 verified that the main chain is bearing an isoxazolidine ring. The molecular weight was found to be in the region of 28900−3600 (Mw) and 6600−1500 g/mol (Mn) according to SEC measurements. It was not possible to determine glass transition temperatures (Tg) for 17 by DSC measurements; for 5 and 13, Tg values were found at 67 and 52 °C, respectively. Decomposition temperatures (Td) for polymer samples 5, 13 and 17 were 260, 247, and 192 °C, respectively. Polymer 17 exhibits good ability for coating formation on a glass surface.